Teens lose almost 3 hours of sleep a day from early school bells, researchers say

Adolescents' circadian rhythm is different from adults', meaning they tend to stay up later at night and sleep in later in the morning.AP File Photo

LANSING -- Starting middle and high school classes early in the morning costs students almost three hours of sleep a day, research from the Education Commission of the States found, and the loss of sleep has a big effect on academic performance.

The report, produced by researchers from the University of Oxford in England and the University of Maryland, examined a wide variety of studies looking at the effect lost sleep has on alertness and how delaying start times for school has affected students.

"There is virtually unanimous agreement in the research community that later start times in adolescent education would produce a positive change in adolescent learning, health and safety. Leading researchers in sleep medicine and sleep neuroscience have frequently called for this change in education start times to improve learning and reduce health risks. Few, if any, educational interventions are so strongly supported by research evidence from so many different disciplines and experts in the field," researchers Paul Kelley and Clark Lee wrote.

On average, adolescent students lose about 2.7 hours of sleep because their natural circadian rhythms make them fall asleep later and wake later, Kelley and Lee found. The change in rhythms means that a teen waking up at 7 a.m. is roughly equivalent to an adult waking at 4 a.m., the researchers wrote.

Internationally, some countries have moved to mandate later start times for older students, the researchers wrote.

"Already, schools in the United Kingdom and New Zealand start at 10 a.m. or later for older adolescents, with strong positive impacts on achievement and behaviors," the report states.

The report does acknowledge that some challenges would accompany moving start times to later in the morning, however.

"Changing community habits based on conventional wisdom can be difficult and needs to be handled confidently. Current early start times have determined timing of other activities (bus transportation and student athletics, for example) and organizers of these activities may resist change," the researchers wrote.

Kelley said in a statement announcing the report's release that lawmakers at all levels of government should consider encouraging schools to change high school bell times.

"There are undoubtedly pragmatic reasons to avoid change," Kelley said. "These are not reasons, however, for stakeholders to avoid considering options for reasonable and appropriate changes to school start times."